Add CommonsChest for shared inventory access across agents

[daveey]

TL;DR

Added a new CommonsChest object that uses the commons inventory instead of its own, enabling shared resource access across agents.

What changed?

• Created a new CommonsChest class that extends Chest but uses the commons inventory
• Added CommonsChestConfig to configure these chests
• Modified HasInventory to add a get_accessible_inventory() method for inventory access
• Updated the chest's onUse method to support fallback to default vibe (0) when agent's vibe isn't configured
• Enhanced agent reward system to support commons inventory-based rewards via commons.{resource}.amount stats
• Added support for commons inventory rewards in the Python configuration
• Updated the cogsguard recipe to use the new CommonsChest for resource management

How to test?

1. Run the cogsguard recipe which now uses CommonsChest objects for resource management
2. Verify that agents can deposit and withdraw resources from the commons inventory
3. Check that agents receive rewards based on the commons inventory levels
4. Test the fallback behavior when an agent's vibe isn't explicitly configured in the chest

Why make this change?

This change enables more sophisticated commons-based gameplay where multiple agents can share resources through a common inventory. It allows for:

1. Collective resource management where agents contribute to and withdraw from a shared pool
2. Rewarding agents based on the state of the commons, encouraging cooperative behavior
3. Simplifying resource distribution mechanics by having chests that directly interact with the commons
4. Creating more complex economic systems where agents have incentives to maintain shared resources

[daveey]

Warning

This pull request is not mergeable via GitHub because a downstack PR is open. Once all requirements are satisfied, merge this PR as a stack on Graphite.
Learn more

• Add observer_agent_id parameter to obs_features for agent-specific observations #4539
• Add Area of Effect (AOE) resource effects to grid objects #4538
• Add CommonsChest for shared inventory access across agents #4537 👈 (View in Graphite)
• Add Commons system for shared inventories between grid objects #4536
• Rename cog_arena.py to cogsguard.py and remove unused imports #4477
• Enhance attack system with armor, weapons, and configurable loot #4313 : 1 other dependent PR (#4321 )
• Make Transfer action optional and add vibe-triggered attack #4315
• Implement bidirectional resource transfer system with vibe-based triggers #4314
• Replace number_of_vibes with explicit vibes list in change_vibe action config #4489
• Refactor inventory system into dedicated InventoryConfig class #4356 : 2 other dependent PRs (#4328 , #4355 )
• Add ignore_limits parameter to inventory updates for initial setup #4360
• Rename test_performance to run_performance in mettagrid to avoid running in pytest #4370
• main

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